As Jason Kidd tinkered with his roster again Monday night, rotating five-man alignments and swapping players readily, the Nets’ game plan — geared at keeping the powerful Miami Heat on their heels — revolved around point guard Deron Williams. In a 102-96 loss, Williams time and again pounded the ball off the Barclays Center hardwood, lowered his shoulder and bulled his way to the rim. The point guard is 6-foot-3 and 209 pounds, and has spent the postseason wheeling around the court on a pair of gimpy ankles. Nonetheless, last night he scored 13 points, provided open shots for teammates (Williams assisted on seven baskets) and even snatched six rebounds. This series against the champion Miami Heat, which the Nets now trail 3-1, has not been easy for Williams. Mario Chalmers and Norris Cole, Miami’s point guards, are a pesky duo with quick feet and busy hands. Sore ankles have complicated matters for Williams. Before Game 7 of the first-round series against the Toronto Raptors, Williams took injections of cortisone and an anti-inflammatory to diminish the swelling in his left ankle. Over the series’ first three games, Williams had often been a peripheral figure. The Nets gained a foothold Saturday when a couple unheralded reserves stepped into prominent roles. While Mirza Teletovic and Andray Blatche sank shots, Williams was mostly the quiet provider. On nine of the Nets’ 15 3-pointers Saturday, Williams supplied an assist. But his jumper continued to lack sharpness. He hit three of his 11 shots, following a Game 2 loss in Miami in which he missed all nine of his field-goal attempts. Kidd defended his point guard, saying, "Everybody has a different definition of struggling. I think he has been positive on the floor.’ An old point guard himself, Kidd said too much emphasis on the scoring column of the box score masked Williams’ other contributions as the engine of the offense.